#!/bin/sh

# Slackware build script for the Raspberry Pi kernel packages
# Written by Konstantinos Mantzaris (kmanjaris@gmail.com)

# Copyright 2012-2014 Konstantinos Mantzaris <kmanjaris@gmail.com>
# All rights reserved.
#
# The script is based on David Spencers work. For more information please
# visit his project page at http://www.daves-collective.co.uk/raspi/
# Copyright 2012 David Spencer, Baildon, West Yorkshire, U.K.
# All rights reserved.
#
# The kernel configuration used in this script is based on Raspbmc Linux. For
# more information please visit the project page at http://www.raspbmc.com/
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY EXPRESS OR IMPLIED
# WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
# EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
# OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
# OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
# ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


GIT_SRC_LINUX=7193cfe
GIT_RPI_FIRMWARE=408bebd
PKGNAM_SRC=kernel-source-raspi
PKGNAM_MOD=kernel-modules-raspi
PKGNAM_FW=kernel-firmware-raspi
PKGNAM_HDR=kernel-headers-raspi
PKGNAM_INITRD=initrd-raspi
PKGNAM_IMAGE=raspi-slackboot
PKGVER=3.10.36
VERSION=3.10.36
BUILD=${BUILD:-1}
TAG=${TAG:-xsb}

# Automatically determine the architecture we're building on:
if [ -z "$ARCH" ]; then
  case "$( uname -m )" in
    i?86) export ARCH=i486 ;;
    arm*) export ARCH=arm ;;
    # Unless $ARCH is already set, use uname -m for all other archs:
       *) export ARCH=$( uname -m ) ;;
  esac
fi

if [ "$ARCH" = "i486" ]; then
  SLKCFLAGS="-O2 -march=i486 -mtune=i686"
  LIBDIRSUFFIX=""
elif [ "$ARCH" = "i686" ]; then
  SLKCFLAGS="-O2 -march=i686 -mtune=i686"
  LIBDIRSUFFIX=""
elif [ "$ARCH" = "s390" ]; then
  SLKCFLAGS="-O2"
  LIBDIRSUFFIX=""
elif [ "$ARCH" = "x86_64" ]; then
  SLKCFLAGS="-O2 -fPIC"
  LIBDIRSUFFIX="64"
elif [ "$ARCH" = "arm" ]; then
  SLKCFLAGS="-O2 -pipe -mcpu=arm1176jzf-s -mtune=arm1176jzf-s -mfpu=vfp -mfloat-abi=softfp -Wno-psabi"
  LIBDIRSUFFIX=""
fi

# Perform package generation sanity checks
if [ ! -d /usr/src/linux ] ; then
  echo "ERROR : Could not locate kernel source path /usr/src/linux"
  echo "ERROR : Please extract the Raspberry Pi kernel source on /usr/src/linux"
  echo "TIP :: git clone git://github.com/raspberrypi/linux.git /usr/src/linux"
  echo "TIP :: wget https://github.com/raspberrypi/linux/tarball/master linux-raspi.tar.gz"
  echo "TIP :: wget https://github.com/raspberrypi/linux/tarball/rpi-3.10.y -O linux-rpi-${PKGVER}.tar.gz"
  exit 1
fi
if [ ! -f $(pwd)/initrd-versatile.img ] ; then
  echo "ERROR : Could not locate the latest SlackwareARM initrd-versatile.img"
  echo "ERROR : Please copy the latest SlackwareARM versatile initrd image"
  echo "ERROR : in $(pwd)"
  echo "http://www.slackware.org.uk/slackwarearm/slackwarearm-current/isolinux/"
  exit 1
fi
if [ ! -d $(pwd)/firmware ] ; then
  echo "ERROR : Could not locate Rasbberry Pi firmware path ${pwd}/firmware"
  echo "ERROR : Please download the Raspberry Pi firmware from GIT under ${pwd}"
  echo "TIP :: git clone git://github.com/raspberrypi/firmware.git firmware"
  echo "TIP :: wget https://github.com/raspberrypi/firmware/tarball/master -O firmware.tar.gz"
  exit 1
fi
if [ ! -d $(pwd)/linux-firmware ] ; then
  echo "ERROR : Could not locate the kernel firmware path ${pwd}/linux-firmware"
  echo "ERROR : Please download the kernel firmware from GIT under ${pwd}"
  echo "TIP :: git clone git://git.kernel.org/pub/scm/linux/kernel/git/dwmw2/linux-firmware.git linux-firmware"
  exit 1
fi

if [ ! -f $(pwd)/config-3.10 ] ; then
  echo "ERROR : Could not locate the Raspberry Pi vanilla kernel config file ${pwd}/config-3.10"
  echo "ERROR : Please download the Raspberry Pi vanilla kernel config file under ${pwd}"
  echo "TIP :: wget https://raw.github.com/raspberrypi/linux/rpi-3.10.y/arch/arm/configs/bcmrpi_defconfig -O config-3.10"
  exit 1
fi

CWD=$(pwd)
TMP=${TMP:-/tmp}
PKG_SRC=$TMP/package-$PKGNAM_SRC
PKG_MOD=$TMP/package-$PKGNAM_MOD
PKG_FW=$TMP/package-$PKGNAM_FW
PKG_HDR=$TMP/package-$PKGNAM_HDR
PKG_INITRD=$TMP/package-$PKGNAM_INITRD
PKG_IMAGE=$TMP/package-$PKGNAM_IMAGE

rm -rf $PKG_SRC
rm -rf $PKG_MOD
rm -rf $PKG_FW
rm -rf $PKG_HDR
rm -rf $PKG_INITRD
rm -rf $PKG_IMAGE
mkdir -p $TMP $PKG_SRC $PKG_MOD $PKG_FW $PKG_HDR $PKG_INITRD $PKG_IMAGE

# Patch the rasbmc kernel config with RAID and RTC support
cd $CWD
cat $CWD/config-3.10 > $CWD/config
zcat $CWD/config.SlaXBMCRPi.diff.gz | patch -p0 || exit 1

# Compile the kernel and build/install kernel modules
cd /usr/src/linux || exit 1
make mrproper
make clean
cat $CWD/config > /usr/src/linux/.config || exit 1
make zImage || exit 1
make modules || exit 1
make modules_install
cd $CWD
if [ ! -d /lib/modules/$VERSION ] ; then
  echo "ERROR : Could not locate the kernel modules under /lib/modules/$VERSION"
  echo "ERROR : Please compile/install the Raspberry Pi kernel modules first"
  exit 1
fi

# Bundle Kernel Firmware Package
cd $PKG_FW || exit 1
mkdir -p $PKG_FW/lib/firmware
cd $CWD/linux-firmware
cp -a * $PKG_FW/lib/firmware || exit 1
mkdir -p $PKG_FW/install
cat $CWD/slack-desc-firmware > $PKG_FW/install/slack-desc
cd $PKG_FW
/sbin/makepkg -l y -c n $TMP/$PKGNAM_FW-$VERSION-$ARCH-$BUILD$TAG.txz
rm -rf $PKG_FW

# Bundle Kernel Headers Package
cd $PKG_HDR || exit 1
mkdir -p $PKG_HDR/usr
cd /usr/src/linux
make INSTALL_HDR_PATH=$PKG_HDR/usr headers_install || exit 1
mkdir -p $PKG_HDR/install
cat $CWD/slack-desc-headers > $PKG_HDR/install/slack-desc
cd $PKG_HDR
/sbin/makepkg -l y -c n $TMP/$PKGNAM_HDR-$VERSION-$ARCH-$BUILD$TAG.txz
rm -rf $PKG_HDR

# Bundle Kernel Source Package
cd $PKG_SRC || exit 1
mkdir -p $PKG_SRC/usr/src/linux-$VERSION
cd /usr/src/linux
cp -a * .config $PKG_SRC/usr/src/linux-$VERSION || exit 1
cd $PKG_SRC/usr/src
ln -s linux-$VERSION linux
cd linux-$VERSION
make clean
#make prepare
mkdir -p $PKG_SRC/install
cat $CWD/slack-desc-source > $PKG_SRC/install/slack-desc
cd $PKG_SRC
/sbin/makepkg -l y -c n $TMP/$PKGNAM_SRC-$VERSION-$ARCH-$BUILD$TAG.txz
rm -rf $PKG_SRC

# Bundle Kernel Modules Package
cd $PKG_MOD || exit 1
mkdir -p $PKG_MOD/lib/modules
cp -a /lib/modules/$VERSION $PKG_MOD/lib/modules || exit 1
mkdir -p $PKG_MOD/etc/rc.d
cat $CWD/rc.modules.new > $PKG_MOD/etc/rc.d/rc.modules-$VERSION.new
chmod 755 $PKG_MOD/etc/rc.d/rc.modules-$VERSION.new
mkdir -p $PKG_MOD/install
cat $CWD/slack-desc-modules > $PKG_MOD/install/slack-desc

# Write out the doinst.sh:
cat << EOF > $PKG_MOD/install/doinst.sh
config() {
  NEW="\$1"
  OLD="\$(dirname \$NEW)/\$(basename \$NEW .new)"
  # If there's no config file by that name, mv it over:
  if [ ! -r \$OLD ]; then
    mv \$NEW \$OLD
  elif [ "\$(cat \$OLD | md5sum)" = "\$(cat \$NEW | md5sum)" ]; then # toss the redundant copy
    rm \$NEW
  fi
  # Otherwise, we leave the .new copy for the admin to consider...
}
config etc/rc.d/rc.modules-${VERSION}.new

# If rc.modules is a real file, back it up:
if [ -r etc/rc.d/rc.modules -a ! -L etc/rc.d/rc.modules ]; then
  cp -a etc/rc.d/rc.modules etc/rc.d/rc.modules.bak 
fi
# Make rc.modules a symlink if it's not already, but do not replace
# an existing symlink.  You'll have to decide to point at a new version
# of this script on your own...
if [ ! -L etc/rc.d/rc.modules ]; then
  ( cd etc/rc.d ; rm -rf rc.modules )
  ( cd etc/rc.d ; ln -sf rc.modules-${VERSION} rc.modules )
fi

# A good idea whenever kernel modules are added or changed:
if [ -x sbin/depmod ]; then
  chroot . /sbin/depmod -a ${VERSION} 1> /dev/null 2> /dev/null
fi

EOF

cd $PKG_MOD
/sbin/makepkg -l y -c n $TMP/$PKGNAM_MOD-$VERSION-$ARCH-$BUILD$TAG.txz
rm -rf $PKG_MOD

# Prepare initrd.gz boot image based on ARMedSlack initrd-versatile.img
cd $PKG_INITRD || exit 1
zcat $CWD/initrd-versatile.img | cpio -iv
rm -rf $PKG_INITRD/lib/modules/*
cd /usr/src/linux
make modules_install INSTALL_MOD_PATH=$PKG_INITRD
cd $PKG_INITRD
zcat $CWD/initrd.SlaXBMCRPi.diff.gz | patch -p1 || exit 1
cp -a $CWD/rpi_initrd $PKG_INITRD/usr/lib/setup/ || exit 1
find . | cpio -o -v -H newc | gzip -9c > $TMP/initrd.gz
cd $TMP
rm -rf $PKG_INITRD

#read -p "Press [Enter] to bundle the RPi boot image..."
# Bundle the Raspberry Pi boot image
# Let's work in 512B sectors.
# 128 "heads" and 32 "sectors" => 2MiB "cylinders",
# That's 4096 sectors per "cylinder".
# 4 "cylinders" = 8MiB erase block boundary (or 2*4MiB boundaries).
# So keep partition boundaries at 4-cyl multiples for best results.
# That's 16384 sectors per erase block.
# 944 "cylinders" = 1979711488B, which is < 2MB, so fits on a "2Mb" card.
echo "Generating empty image file $TMP/$PKGNAM_IMAGE.img"
dd if=/dev/zero of=$TMP/$PKGNAM_IMAGE.img bs=512 count=$(( 128 * 32 * 944 ))

# Drop in the prepared MBR.
# Partition 1 start       1 end  180223 type 0c
# Partition 2 start  180224 end 1032191 type 82
# Partition 3 start 1032192 end 3866623 type 83
echo "Prepending MBR in empty image file $TMP/$PKGNAM_IMAGE.img"
dd if=$CWD/mbr of=$TMP/$PKGNAM_IMAGE.img bs=512 count=1 conv=notrunc

LOOPDEV=$(losetup -f --show $TMP/$PKGNAM_IMAGE.img)
mdadm --build --verbose --force raspimg --level=linear --raid-devices=1 $LOOPDEV
sleep 5
mkdosfs -I /dev/md/raspimg1
mkswap /dev/md/raspimg2
mkfs -t ext4 -O ^has_journal -E stride=2,stripe-width=1024 -b 4096 /dev/md/raspimg3

echo "Loading RPi boot data into $TMP/$PKGNAM_IMAGE.img"
mount -t vfat /dev/md/raspimg1 $PKG_IMAGE
cd $CWD/firmware/boot
cp -a * $PKG_IMAGE || exit 1
rm $PKG_IMAGE/kernel.img
cp $TMP/initrd.gz $PKG_IMAGE/
cp -v /usr/src/linux/System.map $PKG_IMAGE/
if [ $(echo $VERSION | cut -d. -f2) -le 6 ] ; then
    cp -v /usr/src/linux/arch/arm/boot/zImage $PKG_IMAGE/kernel.img
    LOADADDR="0xa00000"
    SIZE="0x$(printf '%x' $(stat --format='%s' $TMP/initrd.gz))"
else
    cp -v /usr/src/linux/arch/arm/boot/zImage $PKG_IMAGE/kernel-${VERSION}.img
fi
CMDLINE=$(grep CONFIG_CMDLINE= /usr/src/linux/.config |awk -F"\"" '{print $2}')
echo "# Low Risk Overclock Settings" > $PKG_IMAGE/config.txt
echo "#arm_freq=850" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=450" >> $PKG_IMAGE/config.txt
echo "#core_freq=300" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "# Medium Risk Overclock Settings" >> $PKG_IMAGE/config.txt
echo "#arm_freq=900" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=450" >> $PKG_IMAGE/config.txt
echo "#core_freq=450" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "# High Risk Overclock Settings" >> $PKG_IMAGE/config.txt
echo "#arm_freq=1000" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=500" >> $PKG_IMAGE/config.txt
echo "#core_freq=500" >> $PKG_IMAGE/config.txt
echo "#over_voltage=6" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "# May The Force Be With You" >> $PKG_IMAGE/config.txt
echo "#arm_freq=1200" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=550" >> $PKG_IMAGE/config.txt
echo "#core_freq=550" >> $PKG_IMAGE/config.txt
echo "#force_turbo=1" >> $PKG_IMAGE/config.txt
echo "#initial_turbo=30" >> $PKG_IMAGE/config.txt
echo "#over_voltage=8" >> $PKG_IMAGE/config.txt
echo "#current_limit_override=0x5A000020" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "framebuffer_depth=24" >> $PKG_IMAGE/config.txt
echo "gpu_mem_256=128" >> $PKG_IMAGE/config.txt
echo "gpu_mem_512=192" >> $PKG_IMAGE/config.txt
echo "start_x=1" >> $PKG_IMAGE/config.txt
echo "#overscan_left=??" >> $PKG_IMAGE/config.txt
echo "#overscan_right=??" >> $PKG_IMAGE/config.txt
echo "#overscan_top=??" >> $PKG_IMAGE/config.txt
echo "#overscan_bottom=??" >> $PKG_IMAGE/config.txt
if [ $(echo $VERSION | cut -d. -f2) -le 6 ] ; then
    echo "ramfsfile=initrd.gz" >> $PKG_IMAGE/config.txt
    echo "ramfsaddr=$LOADADDR"  >> $PKG_IMAGE/config.txt
    echo "$CMDLINE initrd=$LOADADDR,$SIZE" > $PKG_IMAGE/cmdline.txt
else
    echo "kernel=kernel-${VERSION}.img" >> $PKG_IMAGE/config.txt
    echo "initramfs initrd.gz followkernel" >> $PKG_IMAGE/config.txt
    echo "$CMDLINE" > $PKG_IMAGE/cmdline.txt
fi

cd $TMP
sleep 5
umount -v $PKG_IMAGE
mdadm --stop /dev/md/raspimg
losetup -d $LOOPDEV
xz -v $TMP/$PKGNAM_IMAGE.img

echo "Making RPi boot data available under $PKG_IMAGE"
cd $CWD/firmware/boot
cp -a * $PKG_IMAGE || exit 1
rm $PKG_IMAGE/kernel*.img
cp $TMP/initrd.gz $PKG_IMAGE/
cp -v /usr/src/linux/System.map $PKG_IMAGE/
if [ $(echo $VERSION | cut -d. -f2) -le 6 ] ; then
    cp -v /usr/src/linux/arch/arm/boot/zImage $PKG_IMAGE/kernel.img
    LOADADDR="0xa00000"
    SIZE="0x$(printf '%x' $(stat --format='%s' $TMP/initrd.gz))"
else
    cp -v /usr/src/linux/arch/arm/boot/zImage $PKG_IMAGE/kernel-${VERSION}.img
fi
CMDLINE=$(grep CONFIG_CMDLINE= /usr/src/linux/.config |awk -F"\"" '{print $2}')
echo "# Low Risk Overclock Settings" > $PKG_IMAGE/config.txt
echo "#arm_freq=850" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=450" >> $PKG_IMAGE/config.txt
echo "#core_freq=300" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "# Medium Risk Overclock Settings" >> $PKG_IMAGE/config.txt
echo "#arm_freq=900" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=450" >> $PKG_IMAGE/config.txt
echo "#core_freq=450" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "# High Risk Overclock Settings" >> $PKG_IMAGE/config.txt
echo "#arm_freq=1000" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=500" >> $PKG_IMAGE/config.txt
echo "#core_freq=500" >> $PKG_IMAGE/config.txt
echo "#over_voltage=6" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "# May The Force Be With You" >> $PKG_IMAGE/config.txt
echo "#arm_freq=1200" >> $PKG_IMAGE/config.txt
echo "#sdram_freq=550" >> $PKG_IMAGE/config.txt
echo "#core_freq=550" >> $PKG_IMAGE/config.txt
echo "#force_turbo=1" >> $PKG_IMAGE/config.txt
echo "#initial_turbo=30" >> $PKG_IMAGE/config.txt
echo "#over_voltage=8" >> $PKG_IMAGE/config.txt
echo "#current_limit_override=0x5A000020" >> $PKG_IMAGE/config.txt
echo "#---------------------------------" >> $PKG_IMAGE/config.txt
echo "framebuffer_depth=24" >> $PKG_IMAGE/config.txt
echo "gpu_mem_256=128" >> $PKG_IMAGE/config.txt
echo "gpu_mem_512=192" >> $PKG_IMAGE/config.txt
echo "start_x=1" >> $PKG_IMAGE/config.txt
echo "#overscan_left=??" >> $PKG_IMAGE/config.txt
echo "#overscan_right=??" >> $PKG_IMAGE/config.txt
echo "#overscan_top=??" >> $PKG_IMAGE/config.txt
echo "#overscan_bottom=??" >> $PKG_IMAGE/config.txt
if [ $(echo $VERSION | cut -d. -f2) -le 6 ] ; then
    echo "ramfsfile=initrd.gz" >> $PKG_IMAGE/config.txt
    echo "ramfsaddr=$LOADADDR"  >> $PKG_IMAGE/config.txt
    echo "$CMDLINE initrd=$LOADADDR,$SIZE" > $PKG_IMAGE/cmdline.txt
else
    echo "kernel=kernel-${VERSION}.img" >> $PKG_IMAGE/config.txt
    echo "initramfs initrd.gz followkernel" >> $PKG_IMAGE/config.txt
    echo "$CMDLINE" > $PKG_IMAGE/cmdline.txt
fi